Using a mold for a bowl

I am new to pottery and used a metal bowl for a mold. I did spray with WD40, and my instructor told me to take it home and watch it so it didn't dry too long. That was 2 days ago, but I have it wrapped and inside of a covered plastic bin. The clay is still quite wet. I'm really quite unsure how to get it off of the mold. It doesn't seem to want to come off. Did I wait too long or not long enough? How do I know how and when to remove it? (should have asked her for more direction!). Thanks for any help! Cindy

If its over the outside of the bowl you need to get it off soon. Try some air blown in under rim between clay and metal.
It will crack if it dries onto the form. Try to remove it as soon as it will hold its shape.
Mark

I had a good experience using apples for a mold. Yes, apples!
I needed several medium size round hemispheric forms for one of my projects,
so I cut apples in half and covered them with the rather thin layer of Riverside Grit clay.
It was drying slowly without cracking at all and looked great.
I think any type of vegetables/fruit would work, as long as it is not too perishable.